Now, the observed isotropy of the universe (at large scales) makes the stringent
demand that the wave-function of this embedded BEC has to be spherically symmetric
after all. Henceforth, from an analogy commensurable with a limiting Newtonian
cosmological approximation (see refs.[1]}, [2]}), we shall assume such a
wave-function to be of the form:
\(\Psi (r,t) =\, R(t) \, e^{-r^2(t) /\sigma ^2} \, e^{- i E_0 t/\hbar } \,,\) 
